Miniature relay for use in printed circuits



March 17, 1970 r w. F. J. MATHYS 3,501,720

MINIATURE'RELAY FOR USE IN PRINTED CIRCUITS Original Filed Dec. 28. 1966 2 Sheets-Sheet I I nvenlor MINIATURE RELAY FOR USE IN PRINTED CIRCUITS Jriginal Filed Dec. 28. 1966 W. F. J. MATHYS Match 11, 1970 2 Sheets-Sheet 2 United States Patent Cflice 3,501,720. Patented Mar. 17, 1970 3,501,720 MINIATURE RELAY FOR USE IN PRINTED CIRCUITS Walter Franz Josef Mathys, Horgen, Switzerland, assignor to International Standard Electric Corporation, New York, N.Y., a corporation of Delaware Continuation of application Ser. No. 605,302, Dec. 28, 19 66. This application Nov. 5, 1968, Ser. No. 774,590 Claims priority, application Switzerland, Dec. 28, 1965, 17,963/ 65 Int. Cl. H01h 63/02, 67/02 US. Cl. 335-135 15 Claims ABSTRACT OF THE DISCLOSURE A miniature relay is provided for use in restricted spaces, such as that between printed circuit boards. Steps are provided as integral parts of the relay to support contact elemerits and impart elastic deformation to the contact elements in such a way that good electrical connections can be established between contacts.

This application is a continuation of Ser. No. 605,302, Dec. 28, 1966.

The present invention relates to a miniature relay adapted to be used in printed circuits.

Various relays are known which may be used in printed circuits. Most of these relays have the drawback that either the volume or the height or both are too large. Especially with printed circuit structures in which each printed circuit card is required to be removable individually from the structure, the great height above the card of the usual relays is disturbing since the height of the highest element above the card determines the distance between the cards. For making best use of the 'volume, all circuit elements should have the same height.

It is therefore an object of the present invention to provide a relay having a small height.

It is a further object of the present invention to provide a relay which may be produced in a simple manner and which needs no adjusting operations or preloading operations of contact springs before the assembly.

Accordingly the invention provides a miniature relay which is characterized by comprising a coil former carrying the entire relay structure and serving as a seat for several sets of contact springs, arranged side by side, both at the terminal-side'and at the contact-side, the seat at the contact-side being such that the relative position of the contact springs of each contact set is exactly determined without the need of an individual adjustment or a preceding pre-loading of contact springs.

According to a preferred embodiment of the relay said seat at the contact side is provided with steps, the individual steps being shifted with respect to the seat at the terminal side in such manner that by assembling the relay an elastic deformation of all the contact springs occurs. By this deformation the individual contact springs are pressed on the one hand with the desired pressure against the corresponding steps and on the other hand the desired contact pressure is warranted between two contact springs of one contact.

The invention will be best understood from the following description of an embodiment in conjunction with the accompanying drawing in which.

FIGURE 1 represents a longitudinal sectional view taken in parallel to the longitudinal axis of the coil.

FIGURES 2-4 represent external views of the complete relay package.

The relay comprises a coil former 1, a coil 2, an E- shaped magnetic core 3, a U-shaped armature 4, the open side of which is closed by a riveted flat resilient member 14 of non magnetizable material having four fixing bores, and a contact assembly including the contact springs 10, 11 and 12 for each switching-over contact, the pressing plate 5 and the insulating separators 6 and 7.

The coil former 1 is so arranged that it can carry the entire relay structure. For this purpose said coil former is provided at the one side with a block-shaped widening of the spool flange, said widening having four adjacent bores 15 and a seat face 16 used as a seat for the contact assembly at the terminal side. The spool flange at the other end of the coil former is also provided with a widening having the seat faces 17 and 18, a guiding slot 19 for the actuating card 8 which slot is divided into two portions at the side adjacent the armature, and two bores into which the tubular coil terminals 13 are pressed and fixed by turning over.

The coil former 1 is also provided with a rectangular aperture adapted to receive the intermediate magnet limb of the E-shaped core 3, said aperture being such that the core received therein is fixed by a slight squeezing owing to the elastic deformation of the coil former whereby the latter is stiffened.

The seat face 17 used as a seat for the break-contact springs 10 at the contact side is shifted with respect to the seat face 16 at the terminal side in such manner that by mounting the contact assembly onto the relay an elastic deformation of the break-contact springs 10 results which springs were not bent before the mounting. By said deformation the switching-over contact springs 11, which likewise were not bent before mounting, are also deformed via the contact knobs. The difference in height between the seat face 16 and the seat face 17 and the thickness of the insulating separator 7 are chosen with respect to the characteristics of the material of the contact springs 10 and 11 in such manner that by the assembly operation the desired contact pressure results between the contact knobs of the break-contact and the switching-over contact springs.

The switching-over contact springs 11 are operated by the armature 4 via the card 8. Said card slides in a slot 19 which extends at the contact side about over the whole width of the coil former and which slot is divided into two parts at the armature side. In this manner said card cannot get lost when the contact assembly is in place. The card is provided with one seat face at the contact side for all theswitching-over contact springs, but it is provided with two projecting portions at the armature side which pass between the intermediate magnet limb and the outer magnet limbs of the E-shaped core.

The seat face 18 biases the make-contact springs 12 of which neither is bent before assembly. The position of the seat face and the thickness of the insulating separator are so chosen that the rest position of the contact springs 12 is positively determined and that at the end of the raising of the card 8 by actuating the armature 4 the desired contact pressure results between the contact knobs of the contact springs 11 and 12.

All the contact springs are provided with two contact knobs for each contact. For equalizing the contact pressure of the two contact knobs of one contact, the switching-over contact spring 11 is divided into two parts over its entire free length like a fork, each part being provided with one contact knob.

The contact springs 10, 11 and 12 are provided with narrow terminal lugs 20, 21, 22, respectively, bent over at right angles. The terminal lugs 20 of the break-contact springs 10 are bent downwards outside of the insulating separators 6 and 7 and the pressing plate 5. The terminal lugs 21 of the switching-over contact springs 11 pass through coaxial bores 24 and 25 in the insulating separator 7 and in the pressing plate 5 and pass also through a bore in the make-contact spring 12 which bore has an adequate diameter for insulation purposes. The terminal lugs 22 of the make-contact spring 12 pass through bores 26 in the pressing plate 5. The width of said lugs is so chosen that they fit substantially without clearance in the corresponding bores and act as torsion locking.

The pressing plate 5 one main face of which is used as a seat face for the relay has in its other main face four tubular projecting portions used as insulation between the four screws 9 and the corresponding contact springs. The corresponding bores in the contact springs 10, 11 and 12 and in the insulating separators are so dimensioned that a press fit results between the contact springs and the insulating separators and said tubular portions. Therefore the entire contact assembly can be preassembled without using screws or the ilke. Since a certain length of the tubular portions still projects after the preassembly operation of the contact assembly and since the bores 15 in the coil former are suitably dimensioned, the entire preassembled contact assembly can be pressed upon the wound coil former, still without using screws or the like.

The final fixation of the contact assembly onto the coil former is made by said four screws 9 screwed into threaded bores 23 in the core 3. Said four screws are also threaded into suitably chosen bores of the fiat resilient member 14 riveted to the armature so that for fixing the armature no additional elements are needed. The bores in said flat member are so dimensioned that their diameter corresponds to the core diameter of said screws. For limiting the armature motion with the relay de-energized a projecting lug 27 on the front side of the spool flange on the contact side is provided. Under the action of the contact springs and a suitably chosen biasing of the flat member 14 the armature is held in its rest position.

In an alternative form of the relay the projecting ends of the two outer screws are provided, after a U-shaped armature 4 has been put in place, with undercut nuts of thermoplastic material. The undercut portion engages with clearance into a semicircular notched portion at the outer ends of the two limbs of the armature, and the not undercut portion holds the armature with clearance in this position. For limiting the armature motion with the relay de-energized two projecting lugs, one On each side of the spool flange on the contact side, are provided. In this case the armature is held in its rest position only by the action of the contact springs.

The coil terminals are formed by small tubes so that the terminal wires of the coil may be pushed through said tubes and may be soldered simultaneously with the relay into a printed circuit. The mutual distances between the coil terminals and the terminal lugs of the contact springs are such that the relay can be mounted in a printed circuit having a standard raster.

A practical embodiment of the relay according to the invention has a volume less than 7.5 com. and a height above the printed card of only 12 mm. It has four switching-over contacts, each contact spring being provided with two contact knobs and the contact pressure of both the break-contact and the make-contact being at least 5 grammes per contact knob. With 90 to 140 ampere-turns the rise-times are about 4 to 7 ms. and the fall-times about 2 to 2.5 ms.

While the principles of the invention have been described above in connection with specific apparatus and applications, it is to be understood that this description is made only by way of example and not as a limitation on the scope of the invention.

I claim:

1. A miniature relay comprising:

a coil former supporting a relay structure,

a plurality of sets of contact springs having terminal ends and contact ends,

said coil former including a first seat face integral therewith against which the terminal ends of sets of said contact springs are securely fastened with insulating material secured between the terminal ends,

said coil former including additional seat faces integral therewith providing a plurality of stops against which the contact ends of said sets of contact springs are rested,

said stops providing a series of steps,

said first seat face and said steps being oifset from each other to cause the terminal end of each spring to be offset with respect to the step against which its contact end is rested,

the difference between the position of the securely fastened terminal ends of the springs and the positions of the steps causing a desired elastic deformation in each of the contact springs,

the elastic deformation causing individual contact springs to be pressed, on the one hand, with desired pressure against corresponding steps, and

the elastic deformation producing desired pressure, on the other hand, between two contact springs of one contact,

whereby said steps for supporting contact ends of said spring establish the relative position of the contact springs of each contact set in a desired manner and obviate the need for individual adjustment and preloading of contact springs.

2. A relay according to claim 1, in which:

each of said sets of contact springs including a set of switching-over contact springs,

each contact spring is provided with two contact knobs,

and

the switching-over contact spring is divided forkwise over a portion of its length into two portions each of which carries one contact knob by means of which a good contact is secured for both contact knobs.

3. A relay according to claim 1, in which: terminal lugs for the contacts and for the coil have such mutual distances that the relay can be fitted into a standard raster for printed circuits.

4. A relay according to claim 3, in which:

coil terminals are formed by small tubes so that the terminal wires of the coil may be carried through said tubes and may be soldered simultaneously with the relay into a printed circuit.

5. A relay according to claim 1, in which:

said contact springs are held in their position by a screw threaded into the relay core to exert a torsion lock on the contact springs.

6. A relay according to claim 4, in which:

said torsion lock is increased by rectangularly bending terminal lugs of the individual contact springs and by pushing the terminal lugs through bores of an insulating body.

7. A relay according to claim 6, in which:

the said insulating body, on which the contact springs of make-contacts lie directly and other contact springs lie indirectly via insulating separators, is provided with a number of tubular projecting portions corresponding in number to the number of switching-over contact sets,

said projecting portions used as insulation between said screws and said contact springs are so dimensioned that a press fit results between said tubular portions and the required insulating separators and said contact springs, respectively, and

by means of which press fit the entire contact spring set may be pre-assembled without the aid of addiitonal connection means, further in that the said tubular portions have a length which is sufficient to press said portions with the mounted contact spring sets into corresponding bores in said terminal-side seat face of the coil former by which pressing operation the entire relay may be preassembled without the aid of additional connecting means.

8. A relay according to claim 1, in which:

the coil former comprises an E-shaped core.

9. A relay accordingto claim 8, in which:

the said coil former is formed in such a manner that the intermediate limb of said core may be inserted into a wound coil and is fixed in this position by preloading owing to the elastic deformation of the coil former.

10. A relay according to claim 1, in which:

the relay includes a U-shaped armature of magnetizable material.

11. A relay according to claim 10, in which:

the two limbs of the armature are connected by a fastening spring of non-magnetizable material provided with bores.

12. A relay according to claim 11, in which:

the said fastening spring is provided with bores into which the screws used to fix the contacts may be threaded so that said spring is fixed on the core, the diameter of said bores being nearly equal to the core diameter of said screws.

13. A relay according to claim 10, in which:

a projecting lug is placed on that front side of a spool flange which is remote from the armature fixation, said lug being used to limit the armature motion of the de-energized relay.

14. A relay according to claim 10, in which:

the said armature operates the switching-over contact springs via a flat plate of insulating material being held in a sliding manner in the coil former.

15. A relay according to claim 14, in which:

the said plate of insulating material is provided at the contact side with one seat face for all the switchingover contact springs, and

said plate is provided at the armature side with two small projections projecting through the space between the limbs of the E-shaped core and through two corresponding slots in the coil former, whereby said plate cannot get lost when the contact springs sets are mounted.

References Cited UNITED STATES PATENTS 1,812,545 6/1931 Nilson 335-135 2,454,060 11/1948 Hegy 335-135 3,278,872 10/1966 Maynard 335128 3,308,407 3/1967 Lake 335-128 FOREIGN PATENTS 1,015,537 9/1957 Germany.

25 BERNARD A. GILHEANY, Primary Examiner H. BROOME, Assistant Examiner 

